In front of a noisy, boisterous, and partisan crowd in Madrid's Caja Mágica, a Rafael Nadal-inspired Spain beat Canada 2-0 in straight rubbers to win the inaugural Davis Cup Finals tournament.
The 33-year-old, who is guaranteed to end the year as ATP world number one, beat Canadian Denis Shapovalov 6-3 7-6 (9-7) in straight sets to give the hosts an insurmountable lead in the tie, with the final doubles rubber not played.
It was Spain's sixth Davis Cup title, and their first since 2011.
Earlier, Roberto Bautista Agut had overcome personal family tragedy to defeat teenager Félix Auger-Aliassime 7-6 (7-5) 6-3.
The 119-year-old event was contested for the first time in its new format – a week-long tournament featuring 18 countries billed as the "World Cup of Tennis" – after reforms proposed by investors Kosmos Tennis, led by Barcelona footballer Gerard Piqué.
Nadal, the Beijing 2008 singles champion, Rio 2016 doubles champion alongside Marc López, and 19-time Grand Slam champion, was too much to handle for the 20-year-old Shapovalov as the Spaniard's vastly superior experience told.
With a vocal crowd behind him and King Felipe VI watching on, Nadal's big serves put Shapovalov on the back foot, before breaking the young Canadian at the third time of asking.
Shapovalov kept pace with the world number one in the second set to take Nadal to a tiebreak, and saved two championship points at 4-6 down in the tiebreak.
He then failed to convert a set point and ultimately was not able to pull off what would have been a stunning win as Nadal converted his third World Championship point.
In the first rubber, Bautista played through grief three days after the death of his father to put the hosts ahead against 19-year-old Auger-Aliassime.
The world number nine, speaking to host broadcaster Eurosport through tears, said: "It was very special feeling on the court and I just could go out and try my best, give my best."
The other members of Spain's winning team were Pablo Carreño Busta, Marcel Granollers, Feliciano López, and captain Sergi Bruguera.
Auger-Aliassime was playing in his first match all tournament, having sat out the opening four games through injury while Shapovalov and Vasek Pospisil held the fort for the Canadians.
For Canada, who were in their first Davis Cup final, there was to be no repeat of the scenes of four years ago when Auger-Aliassime and Shapovalov partnered each other to Junior Davis Cup glory on the clay courts of Madrid.